Diffractive head up display for firearms

ABSTRACT

A head up display for firearms is provided, wherein a light valve is employed to create variable images in response to user input. The images from the light valve are entrained in an illuminating beam which intersects a diffractive optic. The diffractive optic includes a recorded infinite focal plane which is reconstructed by the illuminating beam, thereby displaying the image from the light valve at an infinite focal plane which is readily viewed be a user looking through the diffractive optic.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

REFERENCE TO A “SEQUENCE LISTING”

Not Applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to head up displays, and moreparticularly, to a head up display for firearms, wherein a plurality ofimages can be selectively presented to a viewer.

2. Description of Related Art

There are several types of sights used with small arms, such as rifles,shotguns, handguns, bows and other similar hand held weapons includingsights which incorporate holographic images of various one, two andthree dimensional reticle patterns. Prior devices incorporatingholograms are shown in U.S. Pat. Nos. 5,483,362; 4,643,515; 5,151,800;5,815,936; and 6,490,060.

However, a need exists for a head up display for firearms which canprovide a variable or a variety of images in response to user input. Theneed also exists for a compact lightweight head up display system thatcan be cooperatively engaged with firearms.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a head up display for firearms, whereinany of a variety of images can be selectively presented to an operator.In one configuration, a light valve is optically intermediate a beamgenerator and a hologram. The hologram includes a recorded image of aninfinite image plane. The beam generator creates an illuminating beamthat passes through the light valve and the hologram. The illuminatingbeam passes through the light to acquire the information in the lightvalve, then reconstructs the recorded infinite image plane from thehologram. The illuminating beam thus acquires any image in the lightvalve and upon reconstructing the image plane of the hologram,effectively displays the image of the light valve at the infinite imageplan.

As the light valve can present a variety of images, or even a video, thepresent head up display provides a variety of images and hence data thatcan be presented.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a side elevational view of a firearm incorporating the head updisplay.

FIG. 2 is a side elevational view of a firearm incorporating atransmissive diffractive optic.

FIG. 3 is a side elevational view of a firearm incorporating analternative design of the head up display.

FIG. 4 is a perspective view of a firearm incorporating the head updisplay.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a compact head up display 10 for a firearm 12 isshown. The head up display 10 can be cooperatively mounted to any of avariety of handheld, side and small arms such as pistols, rifles,shotguns, automatic, semi-automatic arms, as well as bows, collectivelyreferred to as firearms.

The head up display 10 includes a base 20, a diffractive optic 30connected to the base, a laser 40, a power source 50 for powering thelaser, a light valve 60 and an image generator 70 operatively connectedto the light valve.

Referring to FIGS. 1–4, the base 20 can be any of a variety ofconfigurations that cooperatively engage the firearm 12. The base caninclude any of a variety of clamping or mounting mechanisms such as aWeaver style, picatinny mount or dove tail engagement. It is alsounderstood the base 20 can include a cover or shroud 22 to encase orsubstantially encase or house the remaining components of the head updisplay.

The base 20 is constructed to operatively retain the diffractive optic30, the laser 40, the power source 50, the light valve 60 and the imagegenerator 70 relative to the firearm 12. However, it is understood thataspects of the head up display 10 can be integrated into the firearm 12.For example, the power source 50 and/or image generator 70 can beretained or housed in the firearm 12.

The diffractive optic 30 is connected to the base 20. Although thediffractive optic 30 is shown as fixedly connected to the base 20 it isunderstood the diffractive optic can be moveably connected to the basebetween an operable position and a closed (or transport) position. Inthe fixed or operable position, the diffractive optic 30 is disposed sothat an operator of the firearm 12 can sight through the diffractiveoptic. It is understood the diffractive optic 30 can be reflectiverather than transmissive as seen in FIG. 2. However, as the transmissivediffractive optic has a shorter optical path length than the reflectivediffractive optic, it is preferred the diffractive optic betransmissive.

Preferably, the diffractive optic 30 has power. That is, the diffractiveoptic 30 is one of a focussing diffractive optic, diverging diffractiveoptic or collimating diffractive optic. In one configuration, thediffractive optic 30 is a hologram and is fixedly attached to the base20. In a further configuration, the diffractive optic 30 is atransmissive hologram. A transmissive diffractive optic provides that asan illuminating beam intersects the diffractive optic, the illuminatingbeam is diffracted by and passes through the optic.

In either the permanent or the moveable mounting of the diffractiveoptic 30, it is understood the diffractive optic can be mounted to allowadjustment around one, two or three mutual perpendicular axes. Thus, analignment of the diffractive optic 30 can be performed to accommodatevariations or tolerances in components, as well as wear.

In one configuration, the diffractive optic 30 is a hologram with arecorded image of a ground glass screen. More generally, the recordedimage is preferably that of an image plane at infinity. Thus, atransmissive hologram having a recorded infinite image plane ispreferably employed. It is understood that images for reconstruction canbe recorded in the hologram. However, as such images are permanent andcannot be changed during operation or use of the head up display 10, thehologram can be recorded to provide the image plane at infinity.However, it is understood the image plane can be located adjacent an eyeof the user (intermediate the firearm and the user) or anywhere from thefirearm to infinity. Thus, the image plane can be located from adjacentthe user to infinity.

The laser 40 is connected to the base for projecting an illuminatingbeam to intersect the diffractive optic 30. The laser 40 can directlyilluminate the diffractive optic 30, or alternatively include folding orredirecting optics such as mirrors 42 which define the optic path fromthe laser to the diffractive optic. In one configuration, theilluminating beam from the laser 40 intersects the diffractive optic 30at an inclined angle. That is, the principal ray of the illuminatingbeam is inclined relative to the normal of the diffractive optic 30.

In one configuration, the laser 40 produces a diverging coherent beam. Apreferred laser is a laser diode such as HL6321MG manufactured byHitachi.

In one configuration, the power source 50 includes at least one battery.Depending upon the anticipated power requirements, available space andweight restrictions, the batteries can be N-type batteries or AA or AAAbatteries. It is understood that any type of power source, preferablyportable and small in size can be utilized. The battery type powersource can be disposable or rechargeable.

In one configuration, the base 20 includes a battery compartment sizedto operably retain the batteries when subject to the recoil that can beexperienced in a high caliber firearm. The battery compartment can beformed of a weather resistant, resilient material such as plastic andshaped to include receptacles for receiving the battery(ies) requiredfor power. Further, the battery compartment be selectively closeable orsealable to prevent environmental migration into the compartment.

Alternatively, the firearm 12 can incorporate the power source 50,including any associated batteries. In this configuration, the base 20includes a pair of electrical contacts or pads for providing electricalcommunication between the head up display 10 and the firearm 12.

The light valve 60 is connected to the base 20 and disposed opticallyintermediate the laser 40 and the diffractive optic 30. The light valve60 is selected such that upon illumination by the laser 40, the image ofthe light valve is formed onto the diffractive optic (or intermediateoptics or subsequent projection onto the diffractive optic). The lightvalve 60 can be any of a variety of devices including liquid crystaldisplays or cathode ray tubes. In one configuration, the light valve 60is a transmissive element, such as a liquid crystal display (LCD). It isunderstood the light valve can be a predetermined pattern or image forillumination by the passing laser beam.

The image generator 70 is operably connected to the light valve 60 tocause an image to be formed in the light valve for projection onto thediffractive optic 30. The image generator 30 can be any of a variety ofmechanisms such as an integrated circuit or a computer chip. The imagegenerator 70 can include a plurality of stored images that can beselected by the user in response to changing needs of the user. Forexample different reticle images can be stored in the image generator70. In one configuration, the image generator 70 includes a userinterface for controlling the image generator and selecting the image tobe formed in the light valve 60. The image generator 70 can be poweredby the power source 50. An image generator 70 such as a reflective ortransmissive LCD manufactured (or sold) by Kopin Corporation has beenfound satisfactory.

In a further configuration, it is contemplated the image generator 70can include a video driver for providing moving images to the lightvalve 60. The image generator 70 can also include reticles and rangefinding information.

In a further configuration, the image generator 70 cooperatives with anight vision system 80 for protecting output from the night visionsystem to the light valve 60 and hence the diffractive optic 30. Theoutput signal from the night vision system 80 can be directly connectedto the light valve, or passed through the image generator. The nightvision system can be active or passive. The night vision system can becoupled or connected to the firearm, thereby allowing the operator tosight without looking through cumbersome goggles, monoculars orbinoculars. A satisfactory night vision system 80 is manufactured (orsold) by ITT.

In a further configuration, the head up display 10 can include areceiver or transceiver for receiving information from a remote source.Such information can include targeting information, as well as strategicinformation, thereby allowing silent coordinated operations. As theimages in the head up display are dynamic, the communication with remotesources allows coordination between a plurality of head up displays.

Thus, in an alternative configuration, the night vision system 80 can beseparate from the firearm 12 and head up display 10. This configurationdata from the night vision system 80 is provided via telemetry to thehead up display 10. The head up display 10 can include a receiver (ortransceiver) selected to acquire the data from the remote night visionsystem.

Although the light valve 60 and the image generator 70 are described asseparate elements, it is contemplated the elements can be incorporatedor integrated into a single unitary structure, without departing fromthe present invention.

As seen in FIG. 3, it is understood that a collimating relay 64 can bedisposed in cooperation with the light valve 60, such that the divergingilluminating laser beam passes through a collimating lens to form acollimated beam. The collimated beam then illuminates the light valve 60and passes through a focussing lens which focuses the collimated beamonto the diffractive optic 30.

Referring to FIG. 3, in a further configuration, thermal stabilizationof the laser 40 can be accomplished by employing a diffractive grating44 off axis to the diverging beam via a beam splitter 46 such that aselected wavelength is introduced into the lasing medium of the laser,thereby controlling the output wavelength of the laser.

It is further contemplated that alignment of the light valve 60 withrespect to the diffractive optic 30 can be accomplished by optically orphysically moving the laser relative to one of the diffractive opticand/or the light valve.

In a further configuration, the laser beam can be split between anilluminating beam and a targeting beam TB. That is, the targeting beamis reflected from the firearm to intersect the target, while theilluminating beam passes through the light valve and onto thediffractive optic.

It is also contemplated that a range finder can be incorporated into thehead up display 10. Commercially available range finders can beintegrated into the housing, such that the output of the range finder isinput into the image generator or light valve. Thus, the head up displaycan also provide range information to the user.

Operation

In operation, the image generator 70 cooperates with the light valve 60to form an image in the light valve. The laser 40 is powered by thepower source 50 to create a diverging illuminating coherent beam,wherein at least a portion of the illuminating beam passes through thelight valve 60 such that a resulting image is projected onto thediffractive optic 30. The illuminating laser beam reconstructs therecorded image of the hologram and thus displays the image of the lightvalve 60 at infinity, such that the viewer looking through thediffractive optic sees the display of the light valve.

In the configuration of the head up display employing the video driver,moving images or varying images can be generated in the light valve 60and thus “displayed” at the focal plane recreated by the hologram. Thus,range finding information can be readily displayed without requiring theuser to move their head.

Although the present invention has been described in terms of particularembodiments, it is not limited to these embodiments. Alternativeembodiments, configurations or modifications which will be encompassedby the invention can be made by those skilled in the embodiments,configurations, modifications or equivalents may be included in thespirit and scope of the invention, as defined by the appended claims.

1. A compact head up display for a firearm, comprising: (a) a basecooperatively engaging the firearm; (b) a diffractive optic mounted tothe base; (c) a coherent illuminating beam source for illuminating thediffractive optic; (d) a power source selectively connected to thecoherent illuminating beam source; (e) a light valve opticallyintermediate the diffractive optic and the coherent illuminating beamsource; and (f) an image generator connected to the light valve forcreating an image on the light valve.
 2. The compact head up dIsplay ofclaim 1, wherein the diffractive optic is a hologram.
 3. The compacthead up display of claim 1, wherein the diffractive optic is tilted withrespect to the axis of the coherent illuminating beam source.
 4. Thecompact head up display of claim 1, wherein the diffractive optic is ahologram having a recorded image of an infinitely spaced focal plane. 5.The compact laser sight of claim 1, wherein the light valve is a liquidcrystal diode.
 6. The compact head up display of claim 1, wherein theimage appears as a reconstructed image at a plane located from adjacentthe user to infinity at infinity.
 7. The compact head up display ofclaim 1, wherein the coherent illuminating beam source is a laser. 8.The compact head up display of claim 1, further comprising a rangefinder cooperatively connected to one of the image generator and thelight valve for incorporating range information into the image.
 9. Thecompact head up display of claim 1, further comprising an opticalsurface illuminated by the coherent illuminating beam source to form atargeting beam of coherent light.
 10. The compact head up display ofclaim 1, wherein the diffractive optic is transmissive.
 11. The compacthead up display of claim 1, wherein the diffractive optic is reflective.12. A compact head up display for a handheld firearm, comprising: (a) ahologram mounted relative to the handheld firearm; (b) a laser forilluminating the hologram; (c) an image generator; and (d) a light valveoptically intermediate the hologram and the laser and operably connectedto the image generator.
 13. The compact head up display of claim 12,wherein the hologram is moveable connected to the firearm between aclosed position and an open position.
 14. The compact head up display ofclaim 12, further comprising one of a passive and active night visionsystem operably connected to the light valve.
 15. The compact head updisplay of claim 12, further comprising a range finder operably coupledto the light valve.
 16. The compact head up display of claim 12, whereinthe hologram is transmissive.
 17. The compact head up display of claim12, wherein the hologram is reflective.